The Pareto distribution Random Number Generator (RNG). More...
#include "random-variable-stream.h"
Public Member Functions | |
ParetoRandomVariable () | |
Creates a Pareto distribution RNG with the default values for the mean, the shape, and upper bound. | |
double | GetBound () const |
Returns the upper bound on values that can be returned by this RNG stream. | |
virtual uint32_t | GetInteger () |
Get the next random value drawn from the distribution. | |
uint32_t | GetInteger (uint32_t scale, uint32_t shape, uint32_t bound) |
Get the next random value drawn from the distribution. | |
double | GetScale () const |
Returns the scale parameter for the Pareto distribution returned by this RNG stream. | |
double | GetShape () const |
Returns the shape parameter for the Pareto distribution returned by this RNG stream. | |
double | GetValue () override |
Get the next random value drawn from the distribution. | |
double | GetValue (double scale, double shape, double bound) |
Get the next random value drawn from the distribution. | |
Public Member Functions inherited from ns3::RandomVariableStream | |
RandomVariableStream () | |
Default constructor. | |
RandomVariableStream (const RandomVariableStream &)=delete | |
~RandomVariableStream () override | |
Destructor. | |
int64_t | GetStream () const |
Returns the stream number for the RngStream. | |
bool | IsAntithetic () const |
Check if antithetic values will be generated. | |
RandomVariableStream & | operator= (const RandomVariableStream &)=delete |
void | SetAntithetic (bool isAntithetic) |
Specify whether antithetic values should be generated. | |
void | SetStream (int64_t stream) |
Specifies the stream number for the RngStream. | |
Public Member Functions inherited from ns3::Object | |
Object () | |
Constructor. | |
~Object () override | |
Destructor. | |
void | AggregateObject (Ptr< Object > other) |
Aggregate two Objects together. | |
void | Dispose () |
Dispose of this Object. | |
AggregateIterator | GetAggregateIterator () const |
Get an iterator to the Objects aggregated to this one. | |
TypeId | GetInstanceTypeId () const override |
Get the most derived TypeId for this Object. | |
template<typename T > | |
Ptr< T > | GetObject () const |
Get a pointer to the requested aggregated Object. | |
template<> | |
Ptr< Object > | GetObject () const |
Specialization of () for objects of type ns3::Object. | |
template<typename T > | |
Ptr< T > | GetObject (TypeId tid) const |
Get a pointer to the requested aggregated Object by TypeId. | |
template<> | |
Ptr< Object > | GetObject (TypeId tid) const |
Specialization of (TypeId tid) for objects of type ns3::Object. | |
void | Initialize () |
Invoke DoInitialize on all Objects aggregated to this one. | |
bool | IsInitialized () const |
Check if the object has been initialized. | |
void | UnidirectionalAggregateObject (Ptr< Object > other) |
Aggregate an Object to another Object. | |
Public Member Functions inherited from ns3::SimpleRefCount< Object, ObjectBase, ObjectDeleter > | |
SimpleRefCount () | |
Default constructor. | |
SimpleRefCount (const SimpleRefCount &o) | |
Copy constructor. | |
uint32_t | GetReferenceCount () const |
Get the reference count of the object. | |
SimpleRefCount & | operator= (const SimpleRefCount &o) |
Assignment operator. | |
void | Ref () const |
Increment the reference count. | |
void | Unref () const |
Decrement the reference count. | |
Public Member Functions inherited from ns3::ObjectBase | |
virtual | ~ObjectBase () |
Virtual destructor. | |
void | GetAttribute (std::string name, AttributeValue &value, bool permissive=false) const |
Get the value of an attribute, raising fatal errors if unsuccessful. | |
bool | GetAttributeFailSafe (std::string name, AttributeValue &value) const |
Get the value of an attribute without raising errors. | |
void | SetAttribute (std::string name, const AttributeValue &value) |
Set a single attribute, raising fatal errors if unsuccessful. | |
bool | SetAttributeFailSafe (std::string name, const AttributeValue &value) |
Set a single attribute without raising errors. | |
bool | TraceConnect (std::string name, std::string context, const CallbackBase &cb) |
Connect a TraceSource to a Callback with a context. | |
bool | TraceConnectWithoutContext (std::string name, const CallbackBase &cb) |
Connect a TraceSource to a Callback without a context. | |
bool | TraceDisconnect (std::string name, std::string context, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected with a context. | |
bool | TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb) |
Disconnect from a TraceSource a Callback previously connected without a context. | |
Static Public Member Functions | |
static TypeId | GetTypeId () |
Register this type. | |
Static Public Member Functions inherited from ns3::RandomVariableStream | |
static TypeId | GetTypeId () |
Register this type. | |
Static Public Member Functions inherited from ns3::Object | |
static TypeId | GetTypeId () |
Register this type. | |
Static Public Member Functions inherited from ns3::ObjectBase | |
static TypeId | GetTypeId () |
Get the type ID. | |
Private Attributes | |
double | m_bound |
The upper bound on values that can be returned by this RNG stream. | |
double | m_scale |
The scale parameter for the Pareto distribution returned by this RNG stream. | |
double | m_shape |
The shape parameter for the Pareto distribution returned by this RNG stream. | |
Additional Inherited Members | |
Protected Member Functions inherited from ns3::RandomVariableStream | |
RngStream * | Peek () const |
Get the pointer to the underlying RngStream. | |
Protected Member Functions inherited from ns3::Object | |
Object (const Object &o) | |
Copy an Object. | |
virtual void | DoDispose () |
Destructor implementation. | |
virtual void | DoInitialize () |
Initialize() implementation. | |
virtual void | NotifyNewAggregate () |
Notify all Objects aggregated to this one of a new Object being aggregated. | |
Protected Member Functions inherited from ns3::ObjectBase | |
void | ConstructSelf (const AttributeConstructionList &attributes) |
Complete construction of ObjectBase; invoked by derived classes. | |
virtual void | NotifyConstructionCompleted () |
Notifier called once the ObjectBase is fully constructed. | |
Related Symbols inherited from ns3::ObjectBase | |
static TypeId | GetObjectIid () |
Ensure the TypeId for ObjectBase gets fully configured to anchor the inheritance tree properly. | |
The Pareto distribution Random Number Generator (RNG).
This class supports the creation of objects that return random numbers from a fixed Pareto distribution. It also supports the generation of single random numbers from various Pareto distributions.
The probability density function of a Pareto variable is:
where the minimum value is called the Scale
parameter and is called the Pareto index or Shape
parameter.
The resulting distribution will have mean
and variance
The minimum value can be inferred from the desired mean and the parameter with the equation
The Pareto RNG value is generated by
where is a uniform random variable on [0,1).
Since Pareto distributions can theoretically return unbounded values, it is sometimes useful to specify a fixed upper Bound
. The bounded version is defined over the interval . Note however when the upper limit is specified, the mean of the resulting distribution is slightly smaller than the mean value in the unbounded case.
Here is an example of how to use this class:
If an instance of this RNG is configured to return antithetic values, the actual value returned, , is generated as follows:
which now involves the distance is from 1 in the denominator.
ns3::ParetoRandomVariable is accessible through the following paths with Config::Set and Config::Connect:
No TraceSources are defined for this type.
Group: Core
Size of this type is 104 bytes (on a 64-bit architecture).
Definition at line 674 of file random-variable-stream.h.
ns3::ParetoRandomVariable::ParetoRandomVariable | ( | ) |
Creates a Pareto distribution RNG with the default values for the mean, the shape, and upper bound.
Definition at line 477 of file random-variable-stream.cc.
References NS_LOG_FUNCTION.
double ns3::ParetoRandomVariable::GetBound | ( | ) | const |
Returns the upper bound on values that can be returned by this RNG stream.
Definition at line 497 of file random-variable-stream.cc.
References m_bound.
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virtual |
Get the next random value drawn from the distribution.
Reimplemented from ns3::RandomVariableStream.
Definition at line 144 of file random-variable-stream.cc.
Get the next random value drawn from the distribution.
[in] | scale | Mean parameter for the Pareto distribution. |
[in] | shape | Shape parameter for the Pareto distribution. |
[in] | bound | Upper bound on values returned. |
Definition at line 528 of file random-variable-stream.cc.
References ns3::RandomVariableStream::GetStream(), GetValue(), and NS_LOG_DEBUG.
double ns3::ParetoRandomVariable::GetScale | ( | ) | const |
Returns the scale parameter for the Pareto distribution returned by this RNG stream.
Definition at line 485 of file random-variable-stream.cc.
References m_scale.
double ns3::ParetoRandomVariable::GetShape | ( | ) | const |
Returns the shape parameter for the Pareto distribution returned by this RNG stream.
Definition at line 491 of file random-variable-stream.cc.
References m_shape.
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static |
Register this type.
Definition at line 449 of file random-variable-stream.cc.
References m_bound, m_scale, m_shape, ns3::MakeDoubleAccessor(), ns3::MakeDoubleChecker(), and ns3::TypeId::SetParent().
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overridevirtual |
Get the next random value drawn from the distribution.
Implements ns3::RandomVariableStream.
Definition at line 537 of file random-variable-stream.cc.
References GetValue(), m_bound, m_scale, and m_shape.
Referenced by GetInteger(), and GetValue().
Get the next random value drawn from the distribution.
[in] | scale | Mean parameter for the Pareto distribution. |
[in] | shape | Shape parameter for the Pareto distribution. |
[in] | bound | Upper bound on values returned. |
Definition at line 503 of file random-variable-stream.cc.
References ns3::RandomVariableStream::GetStream(), ns3::RandomVariableStream::IsAntithetic(), NS_LOG_DEBUG, ns3::RandomVariableStream::Peek(), and ns3::RngStream::RandU01().
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private |
The upper bound on values that can be returned by this RNG stream.
Definition at line 730 of file random-variable-stream.h.
Referenced by GetBound(), GetTypeId(), and GetValue().
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private |
The scale parameter for the Pareto distribution returned by this RNG stream.
Definition at line 724 of file random-variable-stream.h.
Referenced by GetScale(), GetTypeId(), and GetValue().
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private |
The shape parameter for the Pareto distribution returned by this RNG stream.
Definition at line 727 of file random-variable-stream.h.
Referenced by GetShape(), GetTypeId(), and GetValue().